We asked our readers to send us their most pressing questions on Alzheimer’s disease. The thing on everyone’s mind? Diet and Alzheimer’s. We took your questions about low-carb diets, low-fat diets and supplements like vitamins B12 and D to a community of experts, and here’s what they had to say.
Is it true that certain changes in the diet can prevent, stop & reverse Alzheimer’s?
According to Miia Kivipelto, one of the chief researchers on the groundbreaking FINGER study, a randomized control trial that investigated the effects of lifestyle changes on risk of dementia, if you make changes to your diet, along with other lifestyle changes, the risk of dementia is reduced by 30 percent.
So far there’s no validated, scientific research to back up claims that changes to diet can reverse or stop Alzheimer’s. But Dr. Kivipelto is currently conducting a trial for people with mild Alzheimer’s disease, using the same interventions as the FINGER study, along with nutritionally enhanced foods, to see if it slows the progress of the disease.
Here’s what she recommended: “We normally say at least five portions of fruit and vegetables a day and replace saturated fats with olive oil or rapeseed oil. In terms of brain healthy components, there’s been a lot of focus on nuts recently. Fish is also good—at least two times per week—and, if possible, at least one of these times should be fatty fish because fish oils are known to be good for the brain.”
You can find the full interview here.
I’ve read some suggestions that a low-carb diet may be helpful for Alzheimer’s, and I’ve also read the contrary. What’s the latest thinking on this, and how does a low-carb diet compare to a Mediterranean, low-fat, or standard American (neither low-carb nor low-fat) diet for Alzheimer’s prevention?
Dr. Laura Baker, head of the U.S. POINTER study (the American version of the FINGER study), recommends a Mediterranean diet low in refined sugars and saturated fat. She described the standard American diet as a “tragedy for our health” and said that it’s used in clinical trials as an example of an unhealthy diet. According to Dr. Baker, a diet high in fat can increase the risk of heart disease and Type II diabetes. Both health conditions are associated with a higher incidence of Alzheimer’s disease; in the case of Type II diabetes, it’s over 65 percent greater.
As far as a low-carb diet goes, she believes there may be some benefit. Here’s what she had to say: “As we get older, our ability to metabolize glucose becomes less efficient. When someone has a disease like Alzheimer’s, this process goes at a faster rate to the point where brain cells start to starve. In that case, there may be some value in finding an alternative fuel source for the body in the form of ketones. The research on low-carb or no-carb alternatives, like the ketogenic [diet] is still evolving. It may be that ketones are a more effective fuel for the brain at certain stages of the disease but we can’t make a blanket recommendation yet. We still don’t know enough.”
Dr. Roxana Carrare, an expert in draining the brain of beta-amyloid, one of the hallmarks of Alzheimer’s, says that looking after your arteries in mid-life is crucial to helping facilitate the clearance of the toxic plaque from the brain. Her lab’s research also shows that a high-fat diet during pregnancy reduces the ability of the next generation to clear beta-amyloid plaque from the brain. This is also backed up by epidemiological studies carried out by Dr. Rachel Whitmer that have shown a clear link between diabetes, vascular disease and increased risk for dementia.
Are there any supplements that are useful in slowing the progress of the disease, like B12 and D?
The role of supplements, including B12 and D, in preventing disease is a controversial topic and there’s no consensus among the research community about whether they make a difference. It’s thought that having a diet high in vitamins helps to prevent damage to the brain because their antioxidant properties combat the effects of free radicals.
The best evidence for using B12 is a 2010 study, which found that people who take B12 may be at lower risk of developing Alzheimer’s disease than people who take less of the vitamin. Dr. Sudha Seshadri, M.D., an associate professor of neurology at the Boston University School of Medicine, had this to say in an interview with CNN: The relationship between vitamin B12 and Alzheimer’s risk is “complex.” However, “B12 levels, particularly holotranscobalamin levels, likely play a contributory role.”
Vitamin E has also attracted considerable attention from researchers because of its recognized antioxidant properties. But, once again, the evidence isn’t substantial enough to say definitively whether it helps prevent the disease or slow its progress. One clinical trial looking at the effects of taking vitamin E in combination with Selegiline (a drug used to treat tremors in Parkinson’s disease) in people with moderately severe Alzheimer’s showed that those taking the supplement lived longer and were better able to perform daily activities. There was no effect on cognitive test results. There’s currently no other evidence to support its slowing or prevention of cognitive decline.
There are, however, several studies that show a clear link between deficiency in certain vitamins and the development of dementia, including vitamin D and vitamin A. A critical review by the NCBI looking at the effects of taking vitamin C on the risk of dementia concluded that “there is a large body of evidence that maintaining healthy vitamin C levels can have a protective function against age-related cognitive decline and Alzheimer’s disease, but avoiding vitamin C deficiency is likely to be more beneficial than taking supplements on top of a normal, healthy diet.”
Alzheimer’s can be a confusing, highly individualized disease. Send your questions to firstname.lastname@example.org.